Would constant wiping of dry lint-free microcloth on lid cause rubberized coat to wear off? Or am I just being paranoid and for all cases and that it's only the lid edges that wear off? What's the exact thickness of the rubberized coat?

Sort of, the corners of the lid may become shiny faster if the lid is cleaned often.

I don't clean mine often, but when I do I sometimes use a contact cleaner called Kontakt 60, it's normally used to clean faders and contects, in audio equipemnt fx.It has to be done right to avoid blemishes (nothing permanent).

The way to do it is to take a paper towel, soak it in the contact cleaner, and wipe the lid of the ThinPad in a circular fashion, you have to wipe the lid evenly all over, don't lift the paper towel off the lid, in stead slide if off the edge of the lid, so that the contact cleaner forms a even layer on the surface of the lid no puddles.

Let it sit for 20-30 secs or so, so that it dries off a bit, you can blow at it to speed up the process.This will leave the lid kind of greasy, but if you wipe the lid with a dry cloth preferably fiber free, again in circular motions, you'll notice the lid will start looking like new.You can make even the oldest ThinkPad lids look good using this method.

Do it once a year or so tops, you'll notice that the lid will look clean for quite a while if cleaned this way.If the lid gets dirty, but you cleaned it not long ago using the contact cleaner, just wipe the lid with wet (and completely clean) cloth.